Policy and Charging Rules Functions (PCRFs) are network nodes that perform policy and charging functions for a network. The PCRF function is invoked when another node establishes a policy and charging control session with the PCRF. For example, a Packet Data Network (PDN) Gateway (PGW) or other node may establish a session with a PCRF to either obtain policy and charging instructions for sessions involving a given end user or to authorize and set up policy and charging rules associated with a service.
A Diameter routing agent (DRA) assigns sessions to PCRFs and routes messages associated with a session to the PCRF to which the corresponding session has been assigned. Once a session is assigned to a PCRF, all traffic associated with that subscriber and session is typically routed to the same PCRF until the session is terminated.
At some point during a session, however, an assigned PCRF may reach a maximum capacity, for example, during a traffic burst, a traffic storm, situations where a large quantity of background tasks are running, etc., and reach an overloaded state. To date, overloaded PCRFs are configured to respond to requests with a result code indicating that the PCRF is busy. Thus, some requests are simply rejected and not completed successfully. This is problematic, especially for subscribers that have already been assigned to a PCRF, as that subscriber may be denied service for an extended period of time, for example, for at least an amount of time that the PCRF remains overloaded.
Conventional methods of providing intelligent routing within a Diameter network include assigning new subscriber sessions to PCRFs that are not overloaded. This solution fails to address the problem associated with denying requests of subscribers that have previously been assigned to a PCRF.
Accordingly, a need exists for methods, systems, and computer readable media for diverting Diameter traffic from an overloaded PCRF. In some aspects, a DRA is configured to implement intelligent overload control via diverting Diameter traffic from an overloaded PCRF.